BACKGROUND: The process of cleaning and shaping the canal is not an easy goal to obtain, as canal curvature played a significant role during the instrumentation of the curved canals. AIM: The present in vivo study was conducted to evaluate procedural errors during the preparation of curved root canals using hand Nitiflex and rotary K3XF instruments. MATERIALS AND METHODS: Procedural errors such as ledge formation, instrument separation, and perforation (apical, furcal, strip) were determined in sixty patients, divided into two groups...

INTRODUCTION: The purpose of this study was to introduce a new fatigue test model that simulates the clinical situation for evaluating the corrosion effect of 5.25% sodium hypochlorite (NaOCl) on nickel-titanium (NiTi) files and to evaluate the effect of 3 different temperatures (22°C, 37°C, and 60°C) on the cyclic fatigue of these files. METHODS: Three NiTi files (size 25/.04), K3 (SybronEndo, Orange, CA), K3XF (SybronEndo), and Vortex (Dentsply Tulsa Dental Specialties, Tulsa, OK), were subjected to cyclic fatigue tests inside a novel artificial ceramic canal with a curvature of 60° and a 5-mm radius...

INTRODUCTION: This in vitro study was designed to evaluate the amount of apically extruded irrigant and debris during root canal preparation using K3XF instruments (SybronEndo, Orange, CA) with different kinematics and using hand files with a step-back technique. METHODS: A total of 80 extracted mandibular premolars were selected and randomly assigned to 4 groups (n = 20). The root canals were instrumented with K-type stainless steel instruments using a step-back technique and with the K3XF system using the following kinematics: reciprocating motion, adaptive motion, and continuous rotation...

OBJECTIVE: The aim of this study was to compare the incidence of root cracks after root canal instrumentation with thermomechanically processed nickel-titanium (Ni-Ti) files with different instrumentation kinematics. MATERIALS AND METHODS: A total of 150 extracted mandibular premolars with mature apices and straight root canals were divided into five groups and used in this study. In Group 1, 30 teeth were prepared using hand K-files and assigned to control group, Group 2 was instrumented using K3XF Rotary files (SybronEndo, Glendora, CA, USA) with continuous rotary motion...

BACKGROUND: This study aims to evaluate the frequency of dentinal defects after root canal preparation with the ProTaper NEXT, K3XF and WaveOne GOLD systems using microcomputed tomography. METHODS: Sixty permanent mandibular incisors with a single canal were selected. Inspection of the teeth was performed under a stereomicroscope (15x) to observe the presence of pre-existing cracks and fractures lines. Samples were divided into three experimental groups (n = 20): ProTaper NEXT (PTN), K3XF (K3XF) and WaveOne GOLD (WOG)...

INTRODUCTION: The purpose of this study was to evaluate differences in torsional resistance using up-regulated speed of rotational spindle. METHODS: Three NiTi rotary instrument systems were selected in this study: K3XF (SybronEndo, Glendora, CA), BLX (B&L Biotech, Ansan, Korea), and OneShape (MicroMega, Besançon, France). The tip size and taper for all files were #25 and 0.06. Experimental groups (n = 10/group) were assigned to 2-, 60-, 350-, and 600-rpm groups by the rotational speed of spindle...

BACKGROUND: Micro-CT (μCT) studies that combine simulated canals with meglucamine diatrizoate to evaluate the shaping ability of nickel-titanium (NiTi) rotary instruments are lacking in the literature. The purpose of this study was to evaluate the shaping ability of three new different nickel-titanium rotary instruments in simulated root canals using μCT. METHODS: Thirty simulated root canals with a curvature of 60° were randomly allocated into the following 3 groups (n = 10): Group 1, ProTaper Universal (PTU) rotary system; Group 2, Reciproc single-file system; and Group 3, K3XF rotary system...

The purpose of this study was to compare fracture resistances of K3 nickel-titanium files made from different thermal treatments. K3 (SybronEndo, Orange, CA), K3XF (SybronEndo), and experimentally heat treated K3 (K3H) were used. For the cyclic fatigue test, the samples were rotated with up-and-down motion in the artificial canal with the curvature of 60 degrees until the fracture occurred. The number of cycles to fracture (NCF) was measured. For the torsional fracture test, the samples were tightly bound and rotated until the fracture occurred...

BACKGROUND: The objective of the study was to evaluate and compare how apical enlargement with K3 and K3XF nickel-titanium (NiTi) rotary instruments reduces the root thickness in the danger zone and affects canal transportation and centering ability in mandibular molar mesial canals in a manikin extracted tooth model. MATERIAL AND METHODS: Seventy-two mesial root canals of first mandibular molars were instrumented. Initial and post-instrumentation Cone Beam Computed Tomography scans were performed after root canal preparation up to size 25, 30, 35 and 40 files...

Biomechanical preparation is one of the most important steps in endodontic therapy. Rotary instrumentation has facilitated this step. Nowadays the market is flooded with different types of rotary instruments. The present study compared the root dentinal crack formation with continuous rotating versus reciprocating root canal preparation methods. One hundred and fifty freshly extracted teeth were used for the study. They were divided into 5 groups with 30 teeth in each group. Thirty teeth were kept under control group A and no root canal preparation was done for this group...

AIMS: The aim of this study was to evaluate the number of intracanal bacteria extruded apically during root canal preparation using rotary ProTaper, K3XF, twisted, and hand K-file system. SUBJECTS AND METHODS: Seventy extracted single-rooted human mandibular premolar teeth were used. Access cavities were prepared and the teeth were mounted in glass vials. Root canals were then contaminated with a pure culture of Enterococcus faecalis (ATCC 29212) and incubated at 37°C for 24 h...

INTRODUCTION: The aim of this study was to make a 3-dimensional comparison of the canal transportation and changes in apical geometry using micro-computed tomographic imaging after canal preparation with K3 (SybronEndo, Orange, CA) and K3XF (SybronEndo) file systems. METHODS: Twenty-eight mandibular molars were randomly divided into 2 groups according to the rotary system used in instrumentation: K3 or K3XF. The specimens were scanned by micro-computed tomographic imaging before and after instrumentation...

AIM: To compare the cyclic fatigue resistance of HyFlex CM, Twisted Files (TF), K3XF, Race, and K3, and evaluate the effect of autoclave sterilization on the cyclic fatigue resistance of these instruments both before and after the files were cycled. METHODOLOGY: Five types of NiTi instruments with similar size 30, .06 taper were selected: HyFlex CM, TF, K3XF, Race and K3. Files were tested in a simulated canal with a curvature of 60° and a radius of 3 mm. The number of cycles to failure of each instrument was determined to evaluate cyclic fatigue resistance...

This study was aimed to evaluate the effect of torsional preloads on the cyclic fatigue life of nickel-titanium (NiTi) instruments with different history of heat treatments by manufacturers. WaveOne (Primary) made of M-wire, K3XF (#30/0.06) of R-phase, and ProTaper (F2) of conventional NiTi alloy was used. Each file was preloaded at four conditions (nil, 25, 50, and 75% of their mean ultimate torsional strength) before fatigue testing. The torsional preloads 10-, 30-, or 50-times were applied by securing 5 mm of the file tip, rotating it until the preset torque was attained before returning to the origin...

INTRODUCTION: The purpose of this study was to evaluate the effect of various degrees of cyclic fatigue on torsional failure and torsional preloading on the cyclic fatigue life of heat-treated K3XF nickel-titanium (NiTi) instruments (SybronEndo, Orange, CA). METHODS: The mean number of cycles until failure (Nf) of K3XF and K3 NiTi instruments was examined in a 3-point bending apparatus with a 7-mm radius and 45° curve. Torque and distortion angles at failure of new instruments and instruments stressed to 25%, 50%, and 75% of the Nf were measured according to ISO 3630-1...

AIM: In the present study, the effectiveness of three rotary and two manual nickel titanium instrument systems on mechanical reduction of the intracanal Enterococcus faecalis population was evaluated. METHODS: Mandibular premolars with straight roots were selected. Teeth were decoronated and instrumented until 20 K file and irrigated with physiological saline. After sterilization by ethylene oxide gas, root canals were inoculated with Enterococcus faecalis. The specimens were randomly divided into five groups for canal instrumentation: Manual Nitiflex and Hero Shaper nickel titanium files, and rotary Hyflex CM, ProTaper Next, and K3XF nickel titanium files...